Packaging containers for milk, juice or other beverages are produced in consumer sizes from laminated paper-plastic material which is folded and sealed into packaging containers of the desired shape. A particularly common packaging container is manufactured from a flexible packaging material web which is provided with crease lines and is progressively reformed into a tube and provided with a longitudinal liquid-tight seal. The tube is filled with the desired contents, whereafter at regular spaces it is pressed flat and transversely sealed for the formation of substantially cushion-shaped packaging containers filled with contents. These are thereafter separated from the tube and reformed, int. al. by flat pressing and downward folding of triangular corner flaps, into a parallelepipedic packaging container of known type. The above-described production principle, together with a machine for manufacturing the above container type is described in greater detail in U.S. Pat. No. 3,325,961 and European Patent EP 25235, which are incorporated herein by reference.
The above-disclosed packaging container has, as previously mentioned, a characteristic parallelepipedic basic shape with flat-pressed, substantially triangular corner flaps folded down into abutment against the outside of the packaging container. This form has proved to be highly space efficient and suitable for the transport of large numbers of compactly packed packaging containers. Since the packaging container is, to a particularly high degree, employed for the packing of consumer milk, it has (within certain areas) been so closely related to this type of content that, from the point of view of public relations and distinguishing features, it may be deemed to be less appropriate for other types of contents. This applies in particular when the intention is to pack more expensive and more exclusive products, such as flavoured, refined dairy produce, wine, coffee or tea.
The conventional parallelepipedic package which has been described above displays relatively large side wall panels which the consumer grasps when the packaging container is to be opened and the contents dispensed. In order to avoid the risk, in this operation, that the side wall panels are pressed together more than is desirable, the packaging container must be manufactured from a relatively thick packaging laminate. Alternatively, the packaging container may be designed so that the size of the side wall panels is reduced, which has however proved to be difficult when the current parallelepipedic packaging form is employed for larger volumes.
The above-mentioned, previously known parallelepipedic packaging container is also produced in an aseptic version for packing previously sterilised contents, which hereby obtain, in the packed state, a considerably longer shelf life. Machines and material for producing such aseptic packaging containers are well tested in practice and have proved to possess extraordinarily good reliability and economy.